YouTube Thumbnails turned black

I use Embedded YouTubes on my worpress blog. The You Tube thumbnails were working fine. Now whilst the videos are all still working fine the thumnails are ALL gone. In the place of the thumbnails I have black. Just black and in the middle the “PLay” button is white. Click play and it plays fine. I visited several other wordpress blogs and found same issue.

At YouTube I notice that when I go into the EDIT mode the video viewer is black. The play button is there again in white just as with my thumbnails. Click the white play button and off she goes no worries.

Is this a YouTube problem?